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Cold fusion is a hypothetical type of nuclear reaction that would occur at, or near, room temperature. This is compared with the "hot" fusion which takes place naturally within stars, under immense pressure and at temperatures of millions of degrees, and distinguished from muon-catalyzed fusion. There is currently no accepted theoretical model which would allow cold fusion to occur. In 1989 Martin Fleischmann (then one of the world's leading electrochemists) and Stanley Pons reported that their apparatus had produced anomalous heat ("excess heat") of a magnitude they asserted would defy explanation except in terms of nuclear processes. They further reported measuring small amounts of nuclear reaction byproducts, including neutrons and tritium.〔 ("It is inconceivable that this (of heat ) could be due to anything but nuclear processes... We realise that the results reported here raise more questions than they provide answers...")〕 The small tabletop experiment involved electrolysis of heavy water on the surface of a palladium (Pd) electrode. The reported results received wide media attention, and raised hopes of a cheap and abundant source of energy. Many scientists tried to replicate the experiment with the few details available. Hopes faded due to the large number of negative replications, the withdrawal of many reported positive replications, the discovery of flaws and sources of experimental error in the original experiment, and finally the discovery that Fleischmann and Pons had not actually detected nuclear reaction byproducts.〔, , , 〕 By late 1989, most scientists considered cold fusion claims dead,〔, , , 〕 and cold fusion subsequently gained a reputation as pathological science.〔 〕〔 〕 In 1989, a review panel organized by the United States Department of Energy (DOE) concluded that "the experimental results of excess heat from calorimetric cells reported to date do not present convincing evidence that useful sources of energy will result from the phenomena attributed to cold fusion" and recommended against "any special funding for the investigation of phenomena attributed to cold fusion" or "the establishment of special programs or research centers to develop cold fusion", but was "sympathetic toward modest support" for experiments "within the present funding system." A second DOE review, convened in 2004 to look at new research, reached conclusions similar to the first.〔, , 〕 Subsequently DOE funding for cold fusion research was not realized. A small community of researchers continues to investigate cold fusion,〔, , , , , , "Advocates insist that there is just too much evidence of unusual effects in the thousands of experiments since Pons and Fleischmann to be ignored", , , . calculates between 100 and 200 researchers, with damage to the their careers.〕 now often preferring the designation low-energy nuclear reactions (LENR) or condensed matter nuclear science (CMNS).〔 〕 Since cold fusion articles are rarely published in peer-reviewed mainstream scientific journals, they do not attract the level of scrutiny expected for mainstream scientific publications.〔,〕 ==History== Nuclear fusion is normally understood to occur at temperatures in the tens of millions of degrees. For over 100 years there has been speculation that nuclear fusion might happen at much lower temperatures by fusing hydrogen absorbed in a metal catalyst. In 1989, a claim by Stanley Pons and Martin Fleischmann (then one of the world's leading electrochemists) that such cold fusion had been observed caused a brief media sensation before other scientists began heavily criticizing their claim as being incorrect after many failed to replicate the excess heat. Since the initial announcement, cold fusion research has continued by a small community of committed researchers convinced that such reactions do happen and hoping to gain wider recognition for their experimental evidence. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「cold fusion」の詳細全文を読む スポンサード リンク
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